Production of normal lead dinitroresorcinate



Patented Jan. 3, 1950 UNITED srrss PRODUCTION OF NORMALIEADDINITRORESORCINATE Leon Rubenstein, Saltcoats, Scotland, assignor toImperial Chemical Industries, Limited,a corporation of Great Britain NoDrawing. Application July 8, 1947, Serial No. 759,705. In Great BritainSeptember 4, 1946 7 Claims, (Cl. 260-435) The present invention isconcerned with a new or improved process for the production of normallead salt of 2:4 dinitroresorcinol, whereby said salt may be produced infree-running form without the necessity for coming it.

In Hale U. S. P. 2,116,514 there are described priming compositions forpropellent powders and other explosives, consisting of normal lead 2:4dinitroresorcinate prepared by the action of a lead salt such as leadnitrate on sodium dinitroresorcinate. When prepared in the usual mannerby the addition of a solution of soluble normal lead salt to an aqueoussolution of a normal salt of 2:4 dinitroresorcinol normal lead 2:4dinitroresorcinate has no free flowing properties, and hitherto it hasbeen necessary to corn it with gum arabic before it .can be used forcertain purposes, such as the production of delay fuses, or as anignition agent in detonators.

According to the present invention the process for the production ofnormal lead 2:4 dinitroresorcinate comprises mixing together at atemperature not lower than 60 C. an aqueous solution of normal leadacetate with an aqueous solution containing a magnesium salt of 2:4dinltroresorcinol having about to A the quantity of magnesium present inthe normal magnesium salt, the said lead acetate and magnesium saltbeing admixed in stoichiometrical equivalent weights.

The precipitate thus formed may then be washed with water and dried.

By the term magnesium salt of 2:4 dinitroresorcinol having about /2 tothe quantity of magnesium present in th normal magnesium salt is meant aproduct such as is obtained by interaction of 2:4 dinitroresorcinol andfor example magnesium oxide in /2 to the proportion necessary to givethe normal magnesium salt of 2 :4 dinitroresorcinol.

The pH of the solution containing the magnesuim salt of 2:4dinitroresorcinol having about /2 to the quantity of magnesium presentin the normal magnesium salt is about 3.8 to 5.4 when measured atordinary temperature. This solution may obviously be formed either byaddition of 2:4 dinitroresorcinol to a hot solution of the normalmagnesium salt thereof, or by adding to a hot suspension of 2 4dinitroresorcinol in water from about /2 to of the amount of magnesiumoxide or carbonate required to form the normal magnesium salt.

In carrying out the precipitation the normal lead acetate solution maybe gradually added to the aforesaid solution containing the saidmagnesium salt of 2:4 dinitroresorcinol, or both solutions may be runtogether into water. The precipitation temperature is preferably about70 C.

The resulting free-running normal lead 2:4 dinitroresorcinate may beused as a substitute for lead styphnate as an igniting agent indetonators and the like, for instanc in place of lead styphnate incompositions containing lead styphnate and lead azide together. Mixturesof the said normal lead 2:4 dinitroresorcinate and lead azide show lesstendency to segregation than the azide with lead styphnate. It may alsobe used as a fast burning delay fuse composition in military andcommercial detonators. Since it does not require'to be corned it can beloaded very easily by apparatus employing charging plates.

The invention is illustrated by the following example:

Example 10 gm. of 2:4 dinitroresorcinol are mixed into 150 c. c. ofwater at 80 C. with 1.0 gm. magnesium oxide /2 equivalent), untilsubstantially complete solution is attained. To the filtered solution ofthe resulting acid magnesium salt, maintained at a temperature near 70C. and stirred, 157 c. c. of 12% lead acetate solution are added at aconstant rate over 11 minutes. A curdy orange-yellow precipitate isformed at first, but soon this changes to a dark red dense granularprecipitate. After cooling, filtering and washing with water, thematerial is dried at 40 C.

The slightly lumpy product breaks down on gentle pressure to a dark redfree-running powder.

The product is found to be less sensitive to percussion and friction butsomewhat more sensitive to flame than lead styphnate. It mixes well withlead azide, being superior to lead styphnate in this respect, and theresulting mixtures in proportions around 70% lead azide: 30% normal lead2:4 dinitroresorcinate ignite satisfactorily in detonators for safetyfuse or electric fuseheads, and initiate satisfactorily a base charge oftetryl.

I claim:

1. A process for the production of normal lead 2:4 dinitroresorcinatewhich comprises mixing together at a temperature not lower than 60 C. anaqueous solution of normal lead acetate with an aqueous solutioncontaining a magnesium salt of 2:4 dinitroresorcinol having about V tothe quantity of magnesium present in the normal magnesium salt, the saidlead acetate and mag- 3 nesium salt being admixed in stoichiometricalequivalent weights.

2. A process as claimed in claim 1 wherein the solution containing thesaid magnesium salt of 2:4 dinitroresorcinol is formed by addition of2:4 dinitroresoncinol to a hot solution of the normal magnesium saltthereof.

3. A process as claimed in claim 1 wherein the solution containing thesaid magnesium salt of 2:4 dinitroresorcinol is formed byadding about A;to of the amount of magnesium oxide required to form the normalmagnesium salt to a hot suspension of 2:4 dinitr'oresorcinol in water.

4. A process as claimed in'c'laim '1 wherein the solution containing thesaid magnesium salt of 2:4 dinitroresorcinol is formed by adding /3 toof the amount of magnesium carbonate required to form the normalmagnesium salt to a hot suspension of 2:4 dinitroresorcinol in "water.

5. A process as claimed in claim 1 wherein the solution of normal leadacetate and the solution containing the said magnesium salt of 2:4dinitroresorcinol are run together into water.

6. A process as claimed in claim 1 wherein the temperature of mixing isabout 70CI '7. :A process as claimed in claim 1 wherein the precipitateof normal lead 2:4 dinitroresorcinate formed is washed with Water anddried.

LEON RUBENSTEIN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number

1. A PROCESS FOR THE PRODUCTION OF NORMAL LEAD 2:4 DINITRORESORCINATEWHICH COMPRISES MIXING TOGETHER AT A TEMPERATURE NOT LOWER THAN 60*C. ANAQUEOUS SOLUTION OF NORMAL LEAD ACETATE WITH AN AQUEOUS SOLUTIONCONTAINING A MAGNESIUM SALT OF 2:4 DINITRORESORCINOL HAVING ABOUT 1/2 TO3/4 THE QUANTITY OF MAGNESIUM PRESENT IN THE NORMAL MAGNESIUM SALT, THESAID LEAD ACETATE AND MAGNESIUM SALT BEING ADMIXED IN STOICHIOMETRICALEQUIVALENT WEIGHTS.